Feb. 02, 2021
The current lychee preservation mainly uses low-temperature refrigeration combined with drugs (fungicides, preservatives) treatment, sulphur treatment combined with acid immersion color protection and other technologies, although the shelf life of lychee fruit can be extended to a certain extent, but the pollution of the environment and the potential threat to human health caused by pharmaceutical residues.
Mould is the main factor leading to post-harvest storage of lychee spoilage. Cinnamaldehyde is an essential oil extracted from the edible spice cinnamon, which has a strong killing effect on common food spoilage bacteria and moulds and has also been reported as an antimicrobial agent for mould preservation of fruits and vegetables.
Litchi in storage during the susceptibility to rot-inducing bacteria, compared with disease-free fruit, the early onset of browning of the peel, the surface produces white spots, the later spots produce a large number of black mould on the surface, softening of the peel, water loss inside the fruit decay and discolouration, with sour and rotten taste. Litchi storage during the separation and purification of the main rot-causing bacteria, the dominant rot-causing bacteria 1 strain, named LZF1.
Low mass concentration (10, 50 mg/L) cinnamaldehyde treatment group litchi compared with the control, there is no significant difference between the commercial fruit rate (P>0.05). As the mass concentration of cinnamaldehyde increased, the commercial fruit rate of litchi increased. At a mass concentration of 100 mg/L of cinnamaldehyde, the commercial fruit rate of litchi (42%) was significantly higher than that of the control; at a mass concentration of 500 mg/L, the commercial fruit rate increased to 80%, but there was no significant difference (P > 0.05) between the groups treated with 1,000 mg/L (81.7%) and 5,000 mg/L (83.3%) of cinnamaldehyde.
Different mass concentrations of cinnamaldehyde bacteria significantly reduced the decay index of litchi during storage (P < 0.05). Litchi decay index decreased with increasing mass concentration of cinnamaldehyde, and the decay index of litchi decreased to 0.23 at a mass concentration of 500 mg/L, and there was no significant difference between 1,000 and 5,000 mg/L cinnamaldehyde treatment groups (P > 0.05). Comprehensive commercial fruit rate and decay index, cinnamaldehyde mass concentration 500 mg/L can be considered as the central test point for subsequent orthogonal optimization of antibacterial composite cling film components.
The main decay-causing bacteria causing decay of litchi in the laboratory was black root mould. Cinnamaldehyde antimicrobial composite preservation agent can significantly improve the commercial fruit rate, reduce the decay index, improve the nutritional quality, and effectively improve the storage performance of litchi. The best composite preservative formulation for post-harvest litchi preservation was chitosan mass concentration 1.2 g/100 mL, corn alcohol-soluble protein amount concentration 1.6 g/100 mL, glycerol mass concentration 0.7 g/100 mL, and cinnamaldehyde mass concentration 750 mg/L.
The information is provided by Cinnamaldehyde supplier.